Firefox startup impacted by distributed.net client

[george+freebsd at m5p.com]

OS: FreeBSD post 8.0-RELEASE
Firefox: 3.6
Distributed.net client: v2.9103 and later

When the distributed.net application is not running, Firefox will
start up on my box in less than two seconds.  But with the
distributed.net application running, the firefox startup slows down
painfully, taking no less than 20 seconds, and in extreme cases
up to 90 seconds (out of which it takes 50 seconds for anything
to appear on the screen at all).  Once firefox is started, it
runs very responsively.

distributed.net application is 100% CPU bound,  It takes a chunk
of memory, but it runs at "nice 20" level.  Between firefox and
distributed.net, my system still uses 0% of its swap space according
to swapinfo.  During the startup period, top reports that firefox-bin
is consuming an increasing amount of memory and spending a lot of
time in "ucond" state.

At a guess, something about the way firefox requests memory
causes it to block for some period of time before it can do anything
else.

Has anyone else experienced this?  How should I go about
analyzing it?  Thanks for your help.              -- George Mitchell